In recent years, spatial sound provision from more than two channels has become increasingly popular such as e.g. evidenced by the wide popularity of various surround sounds systems. For example, the increased popularity of home cinema systems has resulted in a surround sound systems being common in many private homes. However, a problem with conventional surround sound systems is that they require a high number of separate speakers located at suitable positions.
For example, a conventional Dolby 5.1 surround sound system requires right and left rear speakers, as well front centre, right and left speakers. In addition, a low frequency subwoofer may be used.
The high number of speakers not only increases cost but also results in reduced practicality and increased inconvenience to users. In particular, it is generally considered a disadvantage that loudspeakers at various positions in front as well as to the rear of listeners are needed. The rear loudspeakers are particularly problematic due to the required wiring and the physical impact they impose on the interior of the room.
In order to mitigate this problem research has been undertaken in order to generate speaker sets that are suitable for reproducing or emulating surround sound systems but using a reduced number of speaker positions. Such speaker sets use directional sound radiation to direct sounds in directions that will result in them reaching the user via reflections from objects in the sound environment. For example, audio signals can be directed so that they will reach the listener via reflections of sidewalls thereby providing an impression to the user that the sound originates to the side (or even behind) the listener.
However, such approaches of providing virtual sound sources tend to be less robust than real sources positioned to the rear of the listener and tend to provide reduced audio quality and a reduced spatial experience. Indeed, it is often difficult to accurately direct audio signals to provide the desired reflections that achieve the desired virtual sound source position. Furthermore, the audio signals intended to be received from the back of the user also tend to reach the user via direct paths or alternative unintended paths thereby degrading the spatial experience.
Hence, an improved surround sound system would be advantageous and in particular a system that will allow facilitated implementation, facilitated setup, a reduced number of speakers, an improved spatial experience, improved audio quality and/or improved performance would be advantageous.